I use the Aperion super tweeters with my RSL CG5's....I like the sizzle, since my all time favorite speakers are German MB Quarts that have a very hot high end.
I have them facing backwards though like Thomas suggests here.
Gives a very spacious soundfield that way...even though technically at 67 years of age, I shouldn't know they are there...but I surely do.
And yes, the subwoofer comparison you cite is nonsense.